Light-duty liquid or gel dishwashing detergent compositions having beneficial skin conditioning, skin feel and rinsability aesthetics

ABSTRACT

Liquid and gel dishwashing detergent compositions which exhibit good cleaning performance and desirable skin feel and rinsability aesthetics are disclosed. Such compositions comprise detergent surfactants, a nonionic surfactant- and hydrotrope-containing skin feel/rinsability enhancing system and small amounts of selected skin conditioning protease enzymes. Such compositions additionally will preferably contain suds boosters and divalent metal cations.

This application claims benefit to provisional application 60/009,994filed Jan. 5, 1996.

TECHNICAL FIELD

The present invention relates to liquid or gel dishwashing detergentcompositions containing detergent surfactants, a skin feel andrinsability enhancement system and low levels of protease enzyme skinconditioning agents to impart consumer preferred skin conditioning, skinfeel and rinsability characteristics to such dishwashing detergentproducts.

BACKGROUND OF THE INVENTION

Light-duty liquid or gel detergent compositions useful for manualdishwashing operations are well known in the art. Such products aregenerally formulated to provide a number of widely diverse performanceproperties and characteristics. First and foremost, liquid or geldishwashing products must be formulated with enough surfactants andother cleaning adjuvants to provide acceptable solubilization andremoval of food soils, especially greasy soils, from dishware beingwashed in aqueous solutions formed from such products.

In addition to being suitable for cleaning dishes, such compositionswill also desirably possess a number of characteristics which enhancethe aesthetics of the manual dishwashing operation. Thus, useful handdishwashing liquids or gels will utilize components which enhance thesudsing performance of the wash solutions formed from such products.Sudsing performance entails both the production of a suitable amount ofsuds in the wash water initially as well as the formation of suds whichlast well into the dishwashing process.

Another aesthetics-related feature of suitable manual dishwashingproducts relates to rinsing performance. Use of highly concentrated orhigh concentrations of dishwashing products can require an increase inthe amount of rinsing that is needed in order to remove detergentcomposition from the dish article once manual agitation and washing iscomplete. For example, in direct application conditions, the disharticle is dampened and the detergent composition is applied to the disharticle in a highly concentrated form or even in its undiluted form.After manual agitation and wiping by the consumer, the article is placedunder running water to be rinsed. The article is thus held under therinsing water until the consumer is satisfied that the remainingdetergent material on the dish article has been removed. Completion ofrinsing is often evaluated by the complete removal of suds from the disharticle and by the lack of a greasy or slippery feel to the dish articleto the touch. Under certain consumer washing conditions such as inambient water conditions and direct application conditions, this problemof achieving complete rinsing is particularly noticeable.

Yet another aesthetics-related feature of suitable manual dishwashingproducts involves the skin "feel" and skin conditioning benefits whichsuch products can impart to dishwashing solutions made therefrom. Withrespect to skin "feel", some consumers prefer that the dishwashingsolution formed from the product not be slimy or slippery feeling totheir hands. Furthermore, acceptable manual dishwashing products shouldalso be mild to the skin, particularly to the hands, and should notcause skin dryness, chapping or roughness. Such skin complaints largelyresult from the removal of natural oils from the skin duringdishwashing. Thus, the manual dishwashing composition should desirablybe effective at removing grease from plates but should not serve toremove natural oils from the skin.

Given the foregoing, there is a continuing need to formulate manualdishwashing liquids and gels that provide an acceptable and desirablebalance between cleaning performance and product aesthetics.Accordingly, it is an object of the present invention to providelight-duty liquid or gel dishwashing compositions which are especiallyeffective at removing food soils from dirty dishware in the context of amanual dishwashing operation.

It is a further object of the present invention to provide suchcompositions having suitable and desirable sudsing performance.

It is the further object of this invention to provide such compositionshaving desirable rinsability characteristics.

It is yet a further object of this invention to provide suchcompositions which impart a desirable non-slippery skin feel to washingsolutions formed therefrom and which provide washing solutions that aredesirably mild and non-irritating to the skin.

It has been found that certain selected combinations of surfactants,hydrotropes and skin conditioning enzymes can be made to providedishwashing compositions which achieve the foregoing objectives. Theelements of this selected combination of ingredients are described asfollows:

SUMMARY OF THE INVENTION

In its composition aspect, the present invention relates to light-dutyliquid or gel dishwashing detergent compositions comprising, by weight,from about 5% to 98% of certain detergent surfactants, from about 3% to20% of a two-component skin feel and rinsability enhancing system andfrom about 0.001% to 5% of an active protease enzyme. Such compositionshave a pH of from about 4 to 11.

The detergent surfactants used in such compositions include polyhydroxyfatty acid amides; nonionic fatty alkypolyglucosides; C₈₋₂₂ alkylsulfates; C₉₋₁₅ alkyl benzene sulfonates, C₈₋₂₂ alkyl ether sulfates;C₈₋₂₂ olefin sulfonates; C₈₋₂₂ paraffin sulfonates; C₈₋₂₂ alkyl glycerylether sulfonates; fatty acid ester sulfonates; secondary alcoholsulfates; C₁₂₋₁₆ alkyl ethoxy carboxylates; C₁₁₋₁₆ secondary soaps;ampholytic detergent surfactants; and zwitterionic detergentsurfactants. Mixtures of these detergent surfactants are alsocontemplated.

The skin feel and rinsability enhancing system essentially comprisesboth an ethoxylated alcohol nonionic surfactant component and ahydrotrope component. The weight ratio of the nonionic surfactantcomponent to the hydrotrope component ranges from about 10:1 to 1:10.

The nonionic surfactant component of the skin feel/rinsability enhancingsystem comprises C₆ -C₁₂ alkanols condensed with from about 5 to 15moles of ethylene oxide. The hydrotrope component of the skinfeel/rinsability enhancing system comprises a material selected from C₁-C₃ alkyl aryl sulfonates, C₆ -C₁₂ alkanols, C₁ -C₆ carboxylic sulfatesand sulfonates, urea, C₁ -C₆ hydrocarboxylates, C₁ -C₄ carboxylates, C₂-C₄ organic diacids and mixtures of these materials.

In its method aspect, the present invention relates to a method forsoaking hands in the context of a manual dishwashing operation, withimproved skin feel andreduced skin irritation resulting therefrom. Sucha method comprises preparing an aqueous dishwashing solution from aneffective amount of a dishwashing detergent composition of the generaltype hereinbefore described and thereafter immersing the hands of thedishwasher in said dishwashing solution for a period of time which iseffective to complete hand dishwashing operations.

DETAILED DESCRIPTION OF THE INVENTION

The light-duty liquid or gel dishwashing detergent compositions of thepresent invention contain three essential components. These componentsare:

(1) detergent surfactants;

(2) a nonionic surfactant- and hydrotrope-containing skin feel andrinsability enhancing system; and

(3) low levels of active protease enzyme.

Optional ingredients can be added to complement or enhance the variousperformance and aesthetics characteristics of the compositions herein.The term "light-duty dishwashing detergent composition" as used hereinrefers to those compositions which are employed in manual (i.e. hand)dishwashing. Such compositions are generally high foaming in nature.

Detergent Surfactants

The compositions of this invention contain from about 5% to about 98%,preferably from about 10% to about 70%, most preferably from about 20%to about 60% of detergent surfactant.

Included in this category are several anionic surfactants commonly usedin liquid or gel dishwashing detergents. The cations associated withthese anionic surfactants are preferably selected from the groupconsisting of calcium, sodium, potassium, magnesium, ammonium oralkanol-ammonium, and mixtures thereof, preferably sodium, ammonium,calcium and magnesium and/or mixtures thereof. Examples of anionicsurfactants that are useful in the present invention are the following:

(1) Alkyl benzene sulfonates in which the alkyl group contains from 9 to15 carbon atoms, preferably 11 to 14 carbon atoms in straight chain orbranched chain configuration. An especially preferred linear alkylbenzene sulfonate contains about 12 carbon atoms. U.S. Pat. Nos.2,220,099 and 2,477,383 describe these surfactants in detail.

(2) Alkyl sulfates obtained by sulfating an alcohol having 8 to 22carbon atoms, preferably 12 to 16 carbon atoms. The alkyl sulfates havethe formula ROSO₃ ⁻ M⁺ where R is the C₈₋₂₂ alkyl group and M is a mono-and/or divalent cation.

(3) Paraffin sulfonates having 8 to 22 carbon atoms, preferably 12 to 16carbon atoms, in the alkyl moiety. Surfactants of this general type arecommercially available as, for example, Hostapur SAS from HoechstCelanese.

(4) Olefin sulfonates having 8 to 22 carbon atoms, preferably 12 to 16carbon atoms. U.S. Pat. No. 3,332,880 contains a description of suitableolefin sulfonates.

(5) Alkyl ether sulfates derived from ethoxylating an alcohol having 8to 22 carbon atoms, preferably 12 to 16 carbon atoms, with less than 30,preferably less than 12, moles of ethylene oxide. The alkyl ethersulfates have the formula:

    RO(C.sub.2 H.sub.4 O).sub.x SO3.sup.- M.sup.+

where R is a C₈₋₂₂ alkyl group, x is 1-30, and M is a mono- or divalentcation. Alkyl ether sulfates are preferred for use herein and willpreferably comprise from about 15% to 35% by weight of the compositionsherein.

(6) Alkyl glyceryl ether sulfonates having 8 to 22 carbon atoms,preferably 12 to 16 carbon atoms, in the alkyl moiety.

(7) Fatty acid ester sulfonates of the formula:

    R.sub.1 --CH(SO.sub.3.sup.- M.sup.+)CO.sub.2 R.sub.2

wherein R₁ is straight or branched alkyl from about C₈ to C₁₈,preferably C₁₂ to C₁₆, and R₂ is straight or branched alkyl from aboutC₁ to C₆, preferably primarily C₁, and M⁺ represents a mono- or divalentcation.

(8) Secondary alcohol sulfates having 6 to 18 carbon atoms, preferably 8to 16 carbon atoms.

(9) Alkyl ethoxy carboxylates of the generic formula

    RO(CH.sub.2 CH.sub.2 O).sub.x CH.sub.2 COO.sup.- M.sup.+

wherein R is a C₁₂ to C₁₆ alkyl group, x ranges from 0 to about 10, andthe ethoxylate distribution is such that, on a weight basis, the amountof material where x is 0 is less than about 20%, preferably less thanabout 15%, most preferably less than about 10%, and the amount ofmaterial where x is greater than 7 is less than about 25%, preferablyless than about 15%, most preferably less than about 10%, the average xis from about 2 to 4 when the average R is C₁₃ or less, and the averagex is from about 3 to 6 when the average R is greater than C₁₃, and M isa cation preferably chosen from alkali metal, ammonium, mono-, di-, andtri-ethanol-ammonium, most preferably from sodium, potassium, ammonium,and mixtures thereof. The preferred alkyl ethoxy carboxylates are thosewhere R is a C₁₂ to C₁₄ alkyl group.

(10) The following general structures illustrate some of the "specialsoaps", or their precursor acids (a.k.a. C₁₁₋₁₆ alkyl carboxyls)employed in this invention:

A. A highly preferred class of soaps used herein comprises the C₁₀ -C₁₆secondary carboxyl materials of the formula R³ CH(R⁴)COOM, wherein R³ isCH₃ (CH₂)_(x) and R⁴ is CH₃ (CH₂)_(y), wherein y can be 0 or an integerfrom 1 to 6, x is an integer from 6 to 12 and the sum of (x+y) is 6-12,preferably 7-11, most preferably 8-9.

B. Another class of special soaps useful herein comprises those carboxylcompounds wherein the carboxyl substituent is on a ring hydrocarbylunit, i.e., secondary soaps of the formula R⁵ --R⁶ --COOM, wherein R⁵ isC₇ --C₁₀, preferably C₈ -C₉, alkyl or alkenyl and R⁶ is a ringstructure, such as benzene, cyclopentane, cyclohexane, and the like.(Note: R⁵ can be in the ortho, meta or para position relative to thecarboxyl on the ring.)

C. Still another class of soaps includes the C₁₀ -C18 primary andsecondary carboxyl compounds of the formula R⁷ CH(R⁸)COOM, wherein thesum of the carbons in R⁷ and R⁸ is 8-16, R⁷ is of the form CH₃--(CHR⁹)_(x) and R⁸ is of the form H--(CHR⁹)_(y), where x and y areintegers in the range 0-15 and R⁹ is H or a C₁₋₄ linear or branchedalkyl group. R⁹ can be any combination of H and C₁₋₄ linear or branchedalkyl group members within a single --(CHR⁹)_(x),y group; however, eachmolecule in this class must contain at least one R⁹ that is not H. Thesetypes of molecules can be made by numerous methods, e.g. byhydroformulation and oxidation of branched olefins, hydroxycarboxylationof branched olefins, oxidation of the products of Guerbet reactioninvolving branched oxoalcohols. The branched olefins can be derived byoligomerization of shorter olefins, e.g. butene, isobutylene, branchedhexene, propylene and pentene.

D. Yet another class of soaps includes the C₁₀ -C₁₈ tertiary carboxylcompounds, e.g., neo-acids, of the formula R¹⁰ CR¹¹ (R¹²)COOM, whereinthe sum of the carbons in R¹⁰, R¹¹ and R¹² is 8-16. R¹⁰, R¹¹, and R¹²are of the form CH₃ --(CHR¹³)_(x), where x is an integer in the range0-13, and R¹³ is H or a C₁₋₄ linear or branched alkyl group. Note thatR¹³ can be any combination of H and C₁₋₄ linear or branched alkyl groupmembers within a single --(CHR¹³)_(x) group. These types of moleculesresult from addition of a carboxyl group to a branched olefin, e.g., bythe Koch reaction. Commercial examples include the neodecanoic acidmanufactured by Exxon, and the Versatic™ acids manufactured by Shell.

In each of the above formulas A, B, C and D, the species M can be anysuitable, especially water-solubilizing, counterion, e.g., H, alkalimetal, alkaline earth metal, ammonium, alkanolammonium, di- and tri-alkanolammonium, C₁ -C₅ alkyl substituted ammonium and the like. Sodiumis convenient, as is diethanolammonium.

Preferred secondary special soaps for use herein are water-solublemembers selected from the group consisting of the water-soluble salts of2-methyl-1-undecanoic acid, 2-ethyl-1-decanoic acid, 2-propyl-1-nonanoicacid, 2-butyl-1-octanoic acid; 2-pentyl-1-heptanoic acid;2-methyl-1-dodecanoic acid; 2-ethyl-1-undecanoic acid;2-propyl-l-decanoic acid; 2-butyl-1-nonanoic acid; 2-pentyl-1-octanoicacid and mixtures thereof

(11) Mixtures of these anionic surfactant types.

The above described anionic surfactants are all available commercially.It should be noted that although both dialkyl sulfosuccinates and fattyacid ester sulfonates will function well at neutral to slightly alkalinepH, they will not be chemically stable in a composition with pH muchgreater than about 8.5.

Other useful surfactants for use in the compositions are the nonionicfatty alkylpolyglucosides. These surfactants contain straight chain orbranched chain C₈ to C₁₅, preferably from about C₁₂ to C₁₄, alkyl groupsand have an average of from about 1 to 5 glucose units, with an averageof 1 to 2 glucose units being most preferred. U.S. Pat. Nos. 4,393,203and 4,732,704, incorporated by reference, describe these surfactants.

The compositions herein may also contain a polyhydroxy fatty acid amidesurfactant of the structural formula: ##STR1## wherein: R¹ is H; C₁ -C₆hydrocarbyl, i.e., C_(p) H_(2p+1) ; 2-hydroxy ethyl; 2-hydroxy propyl;or a mixture thereof, preferably C₁ -C₄ alkyl, more preferably C₁ or C₂alkyl, most preferably C₁ alkyl (i.e., methyl); and R is a C₅ -C₃₁hydrocarbyl, preferably straight chain C₇ -C₁₉ alkyl or alkenyl, morepreferably straight chain C₉ -C₁₇ alkyl or alkenyl, most preferablystraight chain C₁₁ -C₁₇ alkyl or alkenyl, or mixtures thereof; and Z isa polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least3 hydroxyls directly connected to the chain, or an alkoxylatedderivative (preferably ethoxylated or propoxylated) thereof. Zpreferably will be derived from a reducing sugar in a reductiveamination reaction; more preferably Z is a glycityl. Suitable reducingsugars include glucose, fructose, maltose, lactose, galactose, mannose,and xylose. As raw materials, high dextrose corn syrup, high fructosecorn syrup, and high maltose corn syrup can be utilized as well as theindividual sugars listed above. These corn syrups may yield a mix ofsugar components for Z. It should be understood that it is by no meansintended to exclude other suitable raw materials. Z preferably will beselected from the group consisting of --CH₂ --(CHOH)_(n) --CH₂ OH,--CH(CH₂ OH)--(CHOH)_(n-1) --CH₂ OH, --CH₂ --(CHOH)₂ (CHOR')(CHOH)--CH₂OH, where n is an integer from 3 to 5, inclusive, and R' is H or acyclic or aliphatic monosaccharide, and alkoxylated derivatives thereof.Most preferred are glycityls wherein n is 4, particularly --CH₂--(CHOH)₄ --CH₂ OH.

In Formula (I), R¹ can be, for example, N-methyl, N-ethyl, N-propyl,N-isopropyl, N-butyl, N-2-hydroxy ethyl, or N-2-hydroxy propyl.

R² --CO--N< can be, for example, cocamide, stearamide, oleamide,lauramide, myristamide, capricamide, palmitamide, tallowamide, etc.

Z can be 1-deoxyglucityl, 2-deoxyfructityl, 1-deoxymaltityl,1-deoxylactityl, 1-deoxygalactityl, 1-deoxymannityl,1-deoxymaltotriotityl, etc.

Methods for making polyhydroxy fatty acid amides are known in the art.In general, they can be made by reacting an alkyl amine with a reducingsugar in a reductive amination reaction to form a corresponding N-alkylpolyhydroxyamine, and then reacting the N-alkyl polyhydroxyamine with afatty aliphatic ester or triglyceride in a condensation/amidation stepto form the N-alkyl, N-polyhydroxy fatty acid amide product. Processesfor making compositions containing polyhydroxy fatty acid amides aredisclosed, for example, in G.B. Patent Specification 809,060, publishedFeb. 18, 1959, by Thomas Hedley & Co., Ltd., U.S. Pat. No. 2,965,576,issued Dec. 20, 1960 to E. R. Wilson, and U.S. Pat. No. 2,703,798,Anthony M. Schwartz, issued Mar. 8, 1955, U.S. Pat. No. 1,985,424,issued Dec. 25, 1934 to Piggott, 5,188,769, Connor et al, issued Feb.23, 1993 and 5,194,639, Connor et al, issued March 16, 1993, each ofwhich is incorporated herein by reference. Polyhydroxy fatty acid amidesare also highly preferred for use in the dishwashing detergentcompositions herein. Preferably such materials will comprise from about3% to 8% by weight of the composition.

Zwitterionic surfactants include derivatives of aliphatic quaternaryammonium, phosphonium, and sulphonium compounds in which the aliphaticmoiety can be straight or branched chain and wherein one of thealiphatic substituents contains from about 8 to 24 carbon atoms and onecontains an anionic water-solubilizing group. Particularly preferredzwitterionic materials are the ethoxylated ammonium sulfonates andsulfates disclosed in U.S. Pats. Nos. 3,925,262, Laughlin et al, issuedDec. 9, 1975 and 3,929,262, Laughlin et al, issued Dec. 30, 1975, saidpatents being incorporated herein by reference.

Ampholytic surfactants include derivatives of aliphatic or heterocyclicsecondary and ternary amines in which the aliphatic moiety can bestraight chain or branched and wherein one of the aliphatic substituentscontains from about 8 to about 24 carbon atoms and at least onealiphatic substituent contains an anionic water-solubilizing group.

Skin Feel and Rinsability Enhancing System

A second essential component of the dishwashing compositions herein is askin feel and rinsability enhancing system. Such a system will generallycomprise from about 3% to 20% by weight of the compositions herein. Morepreferably the skin feel/rinsability enhancing system will comprise fromabout 4% to 15% by weight of the compositions herein, most preferablyfrom about 6% to 12% by weight of the compositions herein.

The skin feel and rinsability enhancing system itself comprises twocomponents. These are the ethoxylated nonionic surfactant component andthe hydrotrope component.

1) Ethoxylated Nonionic Surfactants

One component of the skin feel/rinsability enhancing system comprises acertain type of relatively short chain ethoxylated alcohol nonionicsurfactant. Such ethoxylated alcohols are the C₆ -C₁₂ alkanols condensedwith from about 5 to 15 moles of ethylene oxide. More preferably, suchnonionic surfactants comprise the C₈ -C₁₁ alkanols condensed with fromabout 8 to 12 moles of ethylene oxide and will be present in thecomposition to the extent of from about 4% to 8% by weight.

2) Hydrotropes

The second component of the skin feel/rinsability enhancing systemcomprises certain types of hydrotrope materials. Hydrotropes suitablefor use in the skin feel/rinsability enhancing system of thecompositions herein include the C₁ -C₃ alkyl aryl sulfonates, C₆ -C₁₂alkanols, C₁ -C₆ carboxylic sulfates and sulfonates, urea, C₁ -C₆hydrocarboxylates, C₁ -C₄ carboxylates, C₂ -C₄ organic diacids andmixtures of these hydrotrope materials.

Suitable C_(1-C) ₃ alkyl aryl sulfonates include sodium, potassium,calcium and ammonium xylene sulfonates; sodium, potassium, calcium andammonium toluene sulfonates; sodium, potassium, calcium and ammoniumcumene sulfonates; and sodium, potassium, calcium and ammoniumsubstituted or unsubstituted naphthalene sulfonates and mixturesthereof.

Suitable C₁ -C₈ carboxylic sulfate or sulfonate salts are any watersoluble salts or organic compounds comprising I to 8 carbon atoms(exclusive of substituent groups), which are substituted with sulfate orsulfonate and have at least one carboxylic group. The substitutedorganic compound may be cyclic, acylic or aromatic, i.e. benzenederivatives. Preferred alkyl compounds have from 1 to 4 carbon atomssubstituted with sulfate or sulfonate and have from 1 to 2 carboxylicgroups. Examples of this type of hydrotrope include sulfosuccinatesalts, sulfophthalic salts, sulfoacetic salts, m-sulfobenzoic acid saltsand diester sulfosuccinates, preferably the sodium or potassium salts asdisclosed in U.S. Pat. No. 3,915,903.

Suitable C₁ -C₄ hydrocarboxylates and C₁ -C₄ carboxylates for use hereininclude acetates and propionates and citrates. Suitable C₂ -C₄ diacidsfor use herein include succinic, glutaric and adipic acids.

Other compounds which deliver hydrotropic effects suitable for useherein as a hydrotrope include C₆ -C₁₂ alkanols and urea.

Preferred hydrotropes for use herein are sodium, potassium, calcium andammonium cumene sulfonate; sodium, potassium, calcium and ammoniumxylene sulfonate; sodium, potassium, calcium and ammonium toluenesulfonate and mixtures thereof. Most preferred are sodium cumenesulfonate and calcium xylene sulfonate and mixtures thereof Thesepreferred hydrotrope materials will be present in the composition to theextent of from about 2% to 7% by weight.

3) Nonionic/Hydrotrope Ratio

Within the skin feel/rinsability enhancing system, the weight ratio ofethoxylated nonionic surfactants to hydrotropes will generally rangefrom about 1:10 to 10:1. More preferably the nonionic/hydrotrope ratiowill range from about 5:1 to 1:5. Most preferably, the ratio of nonionicto hydrotrope will range from about 3:1 to 1:3.

Protease Enzyme

The compositions of this invention will generally contain from about0.001% to about 5%, more preferably from about 0.003% to about 4%, mostpreferably from about 0.005% to about 3%, by weight, of active protease,i.e., proteolytic, enzyme. Protease activity may be expressed in Ansonunits (AU.) per kilogram of detergent composition. Levels of from 0.01to about 150, preferably from about 0.05 to about 80, most preferablyfrom about 0.1 to about 40 AU. per kilogram have been found to beacceptable in compositions of the present invention.

The proteolytic enzyme can be of animal, vegetable or microorganism(preferred) origin. More preferred is serine proteolytic enzyme ofbacterial origin. Purified or nonpurified forms of this enzyme may beused. Proteolytic enzymes produced by chemically or genetically modifiedmutants are included by definition, as are close structural enzymevariants. Particularly preferred is bacterial serine proteolytic enzymeobtained from Bacillus subtilis and/or Bacillus licheniformis.

Suitable proteolytic enzymes include Novo Industri A/S Alcalase®(preferred), Esperase®, Savinase® (Copenhagen, Denmark), Gist-brocades'Maxatase®, Maxacal® and Maxapem 15®) (protein engineered Maxacal®)(Delft, Netherlands), and subtilisin BPN and BPN' (preferred), which arecommercially available. Preferred proteolytic enzymes are also modifiedbacterial serine proteases, such as those made by GenencorInternational, Inc. (San Francisco, Calif.) which are described inEuropean Patent EP-B-251,446, granted Dec. 28, 1994 and published Jan.7, 1988 (particularly pages 17, 24 and 98) and which are also calledherein "Protease B". U.S. Pat. No. 5,030,378, Venegas, issued Jul. 9,1991, refers to a modified bacterial serine proteolytic enzyme (GenencorInternational) which is called "Protease A" herein (same as BPN'). Inparticular see columns 2 and 3 of U.S. Pat. No. 5,030,378 for a completedescription, including amino sequence, of Protease A and its variants.Preferred proteolytic enzymes, then, are selected from the groupconsisting of Alcalase® (Novo Industri A/S), BPN', Protease A andProtease B (Genencor), and mixtures thereof. Protease B is mostpreferred.

Another preferred protease, referred to as "Protease D" is a carbonylhydrolase variant having an amino acid sequence not found in nature,which is derived from a precursor carbonyl hydrolase by substituting adifferent amino acid for a plurality of amino acid residues at aposition in said carbonyl hydrolase equivalent to position +76,preferably also in combination with one or more amino acid residuepositions equivalent to those selected from the group consisting of +99,+101, +103, +104, +107, +123, +27, +105, +109, +126, +128, +135, +156,+166, +195, +197, +204, +206, +210, +216, +217, +218, +222, +260, +265,and/or +274 according to the numbering of Bacillus amyloliquefacienssubtilisin, as described in WO 95/10615 published Apr. 20, 1995 byGenencor International.

Usefil proteases are also described in PCT publications: WO 95/30010published Nov. 9, 1995 by The Procter & Gamble Company; WO 95/30011published Nov. 9, 1995 by The Procter & Gamble Company; WO 95/29979published Nov. 9, 1995 by The Procter & Gamble Company.

Protease enzymes can provide a skin care benefit in the context of thedishwashing detergent products and methods herein. It is believed thatthe protease functions primarily by providing a desquamatory action tothe detergent composition. It is believed that the proteases removedamaged (e.g. dry) skin cells on the surface of the skin, therebyreducing the rough feel associated therewith. The protease removes theeffect of prior damage to the skin, giving the skin a fresher, moreyouthful appearance and feel. When the protease is combined with adetergent surfactant and the skin feel/rinsability enhancing system, theoverall effect is to promote the health of the skin and to provide theconsumer with a perceived mildness or skin feel/appearance advantageover other similar detergent compositions which do not contain proteasewhile still maintaining good cleaning performance.

Composition pH

The dishwashing compositions of the present invention will generallyhave a pH of from about 4 to 11. More preferably, the compositionsherein will be alkaline in nature with a pH of from about 7 to 10.

Dishwashing compositions of the invention will be subjected to acidicstresses created by food soils when put to use, i.e., diluted andapplied to soiled dishes. If a composition with a pH greater than 7 isto be more effective, it should contain a buffering agent capable ofproviding a generally more alkaline pH in the composition and in dilutesolutions, i.e., about 0.1% to 0.4% by weight aqueous solution, of thecomposition. The pKa value of this buffering agent should be about 0.5to 1.0 pH units below the desired pH value of the composition(determined as described above). Preferably, the pKa of the bufferingagent should be from about 7 to about 9.5. Under these conditions thebuffering agent most effectively controls the pH while using the leastamount thereof.

The buffering agent may be an active detergent in its own right, or itmay be a low molecular weight, organic or inorganic material that isused in this composition solely for maintaining an alkaline pH.Preferred buffering agents for compositions of this invention arenitrogen-containing materials. Some examples are amino acids or loweralcohol amines like mono-, di-, and tri-ethanolamine. Other preferrednitrogen-containing buffering agents are2-amino-2-ethyl-1,3-propanediol, 2-amino-2-methyl-propanol,2-amino-2-methyl-1,3-propanediol, tris-(hydroxymethyl)aminomethane(a.k.a. tris) and disodium glutamate. N-methyl diethanolamine,1,3-diamino-2-propanol N,N'-tetramethyl-1,3-diamino-2-propanol,N,N-bis(2-hydroxyethyl)glycine (a.k.a. bicine), and N-tris(hydroxymethyl)methyl glycine (a.k.a. tricine) are also preferred.Mixtures of any of the above are acceptable.

The buffering agent, if used, is present in the compositions of theinvention hereof at a level of from about 0.1% to 15%, preferably fromabout 1% to 10%, most preferably from about 2% to 8%, by weight of thecomposition.

Optional Ingredients

Preferred optional ingredients in the dishwashing compositions hereininclude suds boosters/stabilizers, a stabilizing system for the proteaseenzyme and calcium and/or other inorganic ions. These and other optionalingredients are described as follows:

a) Suds Boosters

The compositions herein will preferably include from about 1% to 20%,preferably from about 2% to 15%, of suds boosters such as betaines,certain relatively long-chain alcohol/ethylene oxide condensates, fattyacid amides, amine oxide semi-polar nonionics, sultaines, complexbetaines and cationic surfactants.

The compositions of this invention can contain betaine detergentsurfactants having the general formula: ##STR2## wherein R is ahydrophobic group selected from the group consisting of alkyl groupscontaining from about 10 to about 22 carbon atoms, preferably from about12 to about 18 carbon atoms, alkyl aryl and aryl alkyl groups containinga similar number of carbon atoms with a benzene ring being treated asequivalent to about 2 carbon atoms, and similar structures interruptedby amido or ether linkages; each R¹ is an alkyl group containing from 1to about 3 carbon atoms; and R² is an alkylene group containing from 1to about 6 carbon atoms.

Examples of preferred betaines are dodecyl dimethyl betaine, cetyldimethyl betaine, dodecyl amidopropyldimethyl betaine,tetradecyldimethyl betaine, tetradecylamidopropyldimethyl betaine, anddodecyldimethylammonium hexanoate.

Other suitable amidoalkylbetaines are disclosed in U.S. Pat. Nos.3,950,417; 4,137,191; and 4,375,421; and British Patent GB No.2,103,236, all of which are incorporated herein by reference.

It will be recognized that the alkyl (and acyl) groups for the abovebetaine surfactants can be derived from either natural or syntheticsources, e,g., they can be derived from naturally occurring fatty acids;olefins such as those prepared by Ziegler, or Oxo processes; or fromolefins separated from petroleum either with or without "cracking".

The alcohol/ethylene oxide condensate suds boosters are broadly definedas compounds produced by the condensation of ethylene oxide groups(hydrophilic in nature) with an organic hydrophobic compound, which canbe aliphatic or alkyl aromatic in nature. The length of the hydrophilicor polyoxyalkylene radical which is condensed with any particularhydrophobic group can be readily adjusted to yield a water-solublecompound having the desired balance between hydrophilic and hydrophobicelements.

Examples of such ethylene oxide condensates suitable as suds stabilizersare the condensation products of relatively long-chain aliphaticalcohols with ethylene oxide. The alkyl chain of the aliphatic alcoholcan either be straight or branched and generally contains from about 14to about 18, preferably from about 14 to about 16, carbon atoms for bestperformance as suds stabilizers, the ethylene oxide being present inamounts of from about 8 moles to about 30, preferably from about 8 toabout 14 moles of ethylene oxide per mole of alcohol.

Examples of the amide surfactants useful as suds boosters herein includethe ammonia, monoethanol, and diethanol amides of fatty acids having anacyl moiety containing from about 8 to about 18 carbon atoms andrepresented by the general formula:

    R.sub.1 --CO--N(H).sub.m-1 (R.sub.2 OH).sub.3-m

wherein R₁ is a saturated or unsaturated, aliphatic hydrocarbon radicalhaving from about 7 to 21, preferably from about 11 to 17 carbon atoms;R₂ represents a methylene or ethylene group; and m is 1, 2, or 3,preferably 1. Specific examples of said amides are mono-ethanol aminecoconut fatty acid amide and diethanol amine dodecyl fatty acid amide.These acyl moieties may be derived from naturally occurring glycerides,e.g., coconut oil, palm oil, soybean oil, and tallow, but can be derivedsynthetically, e.g., by the oxidation of petroleum or by hydrogenationof carbon monoxide by the Fischer-Tropsch process. The monoethanolamides and diethanolamides of C₁₂₋₁₄ fatty acids are preferred.

Amine oxide semi-polar nonionic surfactants comprise compounds andmixtures of compounds having the formula:

    R.sub.1 (C.sub.2 H.sub.4 O).sub.n N.sup.+ R.sub.2 R.sub.3 --O.sup.--

wherein R₁ is an alkyl, 2-hydroxyalkyl, 3-hydroxyalkyl, or3-alkoxy-2-hydroxypropyl radical in which the alkyl and alkoxy,respectively, contain from about 8 to about 18 carbon atoms, R₂ and R₃are each methyl, ethyl, propyl, isopropyl, 2-hydroxyethyl,2-hydroxypropyl, or 3-hydroxypropyl, and n is from 0 to about 10.Particularly preferred are amine oxides of the formula: ##STR3## whereinR₁ is a C₁₂₋₁₆ alkyl and R₂ and R₃ are methyl or ethyl. The aboveethylene oxide condensates, amides, and amine oxides are more fullydescribed in U.S. Pat. No. 4,316,824 (Pancheri), incorporated herein byreference.

The sultaines useful as suds boosters in the present invention are thosecompounds having the formula (R(R¹)₂ N⁺ R² SO₃ -- wherein R is a C₆ -C₁₈hydrocarbyl group, preferably a C₁₀ -C₁₆ alkyl group, more preferably aC₁₂ -C₁₃ alkyl group, each R¹ is typically C₁ -C₃ alkyl, preferablymethyl, and R² is a C₁ -C₆ hydrocarbyl group, preferably a C₁ -C₃alkylene or, preferably, hydroxyalkylene group. Examples of suitablesultaines include C₁₂ -C₁₄ dimethylammonio-2-hydroxypropyl sulfonate,C₁₂₋₁₄ amido propyl ammonio-2-hydroxypropyl sultaine, C₁₂₋₁₄dihydroxyethylammonio propane sulfonate, and C₁₆₋₁₈ dimethylammoniohexane sulfonate, with C₁₂₋₁₄ amido propyl ammonio-2-hydroxypropylsultaine being preferred.

The complex betaines for use as suds boosters herein have the formula:##STR4## wherein R is a hydrocarbon group having from 7 to 22 carbonatoms, A is the group (C(O), n is 0 or 1, R₁ is hydrogen or a loweralkyl group, x is 2 or 3, y is an integer of 0 to 4, Q is the group --R₂COOM wherein R₂ is an alkylene group having from 1 to 6 carbon atoms andM is hydrogen or an ion from the groups alkali metals, alkaline earthmetals, ammonium and substituted ammonium and B is hydrogen or a group Qas defined.

The composition of this invention can also contain certain cationicquaternary ammonium surfactants of the formula:

    [R.sup.1 (OR.sup.2).sub.y ][R.sup.3 (OR.sup.2).sub.y ].sub.2 R.sup.4 N.sup.+ X.sup.-

or amine surfactants of the formula:

    [R.sup.1 (OR.sup.2).sub.y ][R.sup.3 (OR.sup.2).sub.y ]R.sup.4 N

wherein R¹ is an alkyl or alkyl benzyl group having from about 6 toabout 16 carbon atoms in the alkyl chain; each R² is selected from thegroup consisting of --CH₂ CH₂ --, --CH₂ CH(CH₃)--, --CH₂ CH(CH₂ OH)--,--CH₂ CH₂ CH₂ --, and mixtures thereof; each R³ is selected from thegroup consisting of C₁ -C₄ alkyl, C₁ -C₄ hydroxyalkyl, benzyl, andhydrogen when y is not 0; R⁴ is the same as R³ or is an alkyl chainwherein the total number of carbon atoms of R¹ plus R⁴ is from about 8to about 16; each y is from 0 to about 10, and the sum of the y valuesis from 0 to about 15; and X is any compatible anion.

Preferred of the above are the alkyl quaternary ammonium surfactants,especially the mono-long chain alkyl surfactants described in the aboveformula when R⁴ is selected from the same groups as R³. The mostpreferred quaternary ammonium surfactants are the chloride, bromide, andmethylsulfate C₈₋₁₆ alkyl trimethylammonium salts, C₈₋₁₆ alkyldi(hydroxyethyl)methylammonium salts, the C₈₋₁₆ alkylhydroxyethyldimethylammonium salts, C₈₋₁₆ alkyloxypropyltrimethylammonium salts, and the C₈₋₁₆ alkyloxypropyldihydroxyethylmethylammonium salts. Of the above, the C₁₀₋₁₄ alkyltrimethylammonium salts are preferred, e.g., decyl trimethylammoniummethylsulfate, lauryl trimethylammonium chloride, myristyltrimethylammonium bromide and coconut trimethylammonium chloride, andmethylsulfate.

The suds boosters used in the compositions of this invention can containany one or mixture of the suds boosters listed above.

b) Enzyme Stabilizing System

The preferred compositions herein may additionally comprise from about0.001% to about 10%, preferably from about 0.005% to about 8%, mostpreferably from about 0.01% to about 6%, by weight of an enzymestabilizing system. The enzyme stabilizing system can be any stabilizingsystem which is compatible with the protease enzyme of the presentinvention. Such stabilizing systems can comprise calcium ion, boricacid, propylene glycol, short chain carboxylic acid, boronic acid,polyhydroxyl compounds and mixtures thereof such as are described inU.S. Pat. Nos. 4,261,868, Hora et al, issued Apr. 14, 1981; 4,404,115,Tai, issued Sep. 13, 1983; 4,318,818, Letton et al; 4,243,543, Guildertet al issued Jan. 6, 1981; 4,462,922, Boskamp, issued Jul. 31, 1984;4,532,064, Boskamp, issued Jul. 30, 1985; and 4,537,707, Severson Jr.,issued Aug. 27, 1985, all of which are incorporated herein by reference.

Additionally, from 0 to about 10%, preferably from about 0.01% to about6% by weight, of chlorine bleach scavengers can be added to compositionsof the present invention to prevent chlorine bleach species present inmany water supplies from attacking and inactivating the enzymes,especially under alkaline conditions. While chlorine levels in water maybe small, typically in the range from about 0.5 ppm to about 1.75 ppm,the available chlorine in the total volume of water that comes incontact with the enzyme during dishwashing is usually large;accordingly, enzyme stability in-use can be problematic.

Suitable chlorine scavenger anions are salts containing ammoniumcations. These can be selected from the group consisting of reducingmaterials like sulfite, bisulfite, thiosulfite, thiosulfate, iodide,etc., antioxidants like carbamate, ascorbate, etc., organic amines suchas ethylenediaminetetracetic acid (EDTA) or alkali metal salt thereofand monoethanolamine (MEA), and mixtures thereof. Other conventionalscavenging anions like sulfate, bisulfate, carbonate, bicarbonate,percarbonate, nitrate, chloride, borate, sodium perborate tetrahydrate,sodium perborate monohydrate, percarbonate, phosphate, condensedphosphate, acetate, benzoate, citrate, formate, lactate, malate,tartrate, salicylate, etc. and mixtures thereof can also be used. Thepreferred ammonium salts or other salts of the specific chlorinescavenger anions can either replace the suds controlling agent or beadded in addition to the suds controlling agent.

Although ammonium salts can be admixed with the detergent composition,they are prone to adsorb water and/or give off ammonia gas. Accordingly,it is better if they are protected in a particle like that described inU.S. Pat. No. 4,652,392, Baginski et al, which is incorporated herein byreference.

c) Calcium and/or Magnesium Ions

The presence of calcium and/or magnesium (divalent) ions improves thecleaning of greasy soils for various compositions, i.e., compositionscontaining alkyl ethoxy sulfates or carboxylates and/or polyhydroxyfatty acid amides. This is especially true when the compositions areused in softened water that contains few divalent ions. It is believedthat calcium and/or magnesium ions increase the packing of thesurfactants at the oil/water interface, thereby reducing interfacialtension and improving grease cleaning.

Compositions of the invention herein containing magnesium and/or calciumions exhibit good grease removal, manifest mildness to the skin, andprovide good storage stability. The ions are present in the compositionshereof at an active level of from about 0.1% to 4%, preferably fromabout 0.3% to 3.5%, more preferably from about 0.5% to 1%, by weight.

Preferably, the magnesium or calcium ions are added as a hydroxide,chloride, acetate, formate, oxide or nitrate salt to the compositions ofthe present invention. Calcium ions may also be added as salts of thehydrotrope.

The amount of calcium or magnesium ions present in compositions of theinvention will be dependent upon the amount of total surfactant presenttherein, including the amount of alkyl ethoxy carboxylates andpolyhydroxy fatty acid amide. When calcium ions are present in thecompositions of this invention, the molar ratio of calcium ions to totalanionic surfactant is from about 0.25:1 to about 2:1 for compositions ofthe invention.

Formulating such divalent ion-containing compositions in alkaline pHmatrices may be difficult due to the incompatibility of the divalentions, particularly magnesium, with hydroxide ions. When both divalentions and alkaline pH are combined with the surfactant mixture of thisinvention, grease cleaning is achieved that is superior to that obtainedby either alkaline pH or divalent ions alone. Yet, during storage, thestability of these compositions becomes poor due to the formation ofhydroxide precipitates. Therefore, chelating agents discussed hereinbelow may also be necessary.

d) Other Optional Components

In addition to the essential and preferred optional ingredientsdescribed hereinbefore, the compositions contain other conventionalingredients, especially those associated with dishwashing compositions.

The compositions can also contain from about 0.01% to about 15%,preferably from about 1% to about 10%, by weight nonionic detergentsurfactants which do not foam and may even inhibit foaming. Suitablenonionic detergents are disclosed in U.S. Pat. No. 4,321,165, Smith etal (Mar. 23, 1982) 4,316,824 Pancheri (Feb. 234, 1982) and U.S. Pat. No.3,929,678, Laughlin et al., (Dec. 30, 1975). Exemplary, non-limitingclasses of useful nonionic surfactants are listed below.

1. The polyethylene, polypropylene, and polybutylene oxide condensatesof alkyl phenols. In general, the polyethylene oxide condensates arepreferred. These compounds include the condensation products of alkylphenols having an alkyl group containing from 6 to 12 carbon atoms ineither a straight- or branched-chain configuration with the alkyleneoxide. Commercially available nonionic surfactants of this type includeIgepal™ CO-630, marketed by the GAF Corporation; and Triton™ X-45,X-114, X-100, and X-102, all marketed by the Rohm & Haas Company.

2. The condensation products of ethylene oxide with a hydrophobic baseformed by the condensation of propylene oxide with propylene glycol. Thehydrophobic portion of these compounds preferably has a molecular weightof from about 1500 to about 1800 and exhibits water insolubility.

3. The condensation products of ethylene oxide with the productresulting from the reaction of propylene oxide and ethylenediamine.

4. Alkylpolysaccharides disclosed in U.S. Pat. No. 4,565,647, Llenado,issued Jan. 21, 1986, having a hydrophobic group containing from about 6to about 30 carbon atoms, preferably from about 10 to about 16 carbonatoms and a polysaccharide, e.g., a polyglycoside, hydrophilic groupcontaining from about 1.3 to about 10, preferably from about 1.3 toabout 3, most preferably from about 1.3 to about 2.7 saccharide units.U.S. Pat. Nos. 4,393,203 and 4,732,704, incorporated herein byreference, also describe acceptable surfactants.

Other conventional optional ingredients which are usually used inadditive levels of below about 5% include opacifiers, antioxidants,bactericides, dyes, perfumes, and the like.

Optional enzymes such as lipase and/or amylase may be added to thecompositions of the present invention for additional cleaning benefits.

Detergency builders can also be present in amounts from 0% to about 50%,preferably from about 2% to about 30%, most preferably from about 5% toabout 15%. It is typical in light-duty liquid or gel dishwashingdetergent compositions to have no detergent builder present. However,certain compositions containing magnesium or calcium ions may requirethe additional presence of low levels of, preferably from 0 to about10%, more preferably from about 0.5% to about 3%, chelating agentsselected from the group consisting of bicine/bis(2-ethanol)blycine),citrate N-(2-hydroxylethyl) iminodiacetic acid (HIDA),N-(2,3-dihydroxy-propyl) iminodiacetic acid (GIDA), and their alkalimetal salts. Some of these chelating agents are also identified in theart as detergency builders.

The compositions of this invention may contain for chelating anddetergency purposes from about 0.001% to about 15% of certainalkylpolyethoxypolycarboxlyate surfactants of the general formula##STR5## wherein R is a C₆ to C₁₈ alkyl group, x ranges from about 1 toabout 24, R₁ and R₂ are selected from the group consisting of hydrogen,methyl acid radical succinic acid radical hydroxy succinic acid radical,and mixtures thereof, wherein at least one R₁ or R₂ is a succinic acidand/or hydroxysuccinic acid radical. An example of a commerciallyavailable alkylpolyethoxypoly-carboxylate which can be employed in thepresent invention is POLY-TERGENT C, Olin Corporation, Cheshire, Conn.

The alkylpolyethoxypolycarboxylate surfactant is selected on the basisof its degree of hydrophilicity. A balance of carboxylation andethoxylation is required in the alkylpolyethoxypolycarboxylate in orderto achieve maximum chelating benefits without affecting the cleaningbenefits which is associated with the divalent ions or the sudsing ofthe liquid or gel dishwashing detergent compositions. The number ofcarboxylate groups dictates the chelating ability, too muchcarboxylation will result in too strong a chelator and prevent cleaningby the divalent ions. A high degree of ethoxylation is desired formildness and solubility; however, too high a level will affect sudsing.Therefore, an alkylpolyethoxypolycarboxylate with a modest degree ofethoxylation and minimal carboxylation is desirable.

Other desirable ingredients include diluents and solvents. Diluents canbe inorganic salts, such as sodium sulfate, sodium chloride, sodiumbicarbonate, etc., and the solvents include water, lower molecularweight alcohols such as ethyl alcohol, isopropyl alcohol, etc. In liquiddetergent compositions there will typically be from 0% to about 90%,preferably from about 20% to about 70%, most preferably from about 40%to about 60% of water, and from 0% to about 50%, most preferably fromabout 3% to about 10% of ingredients to promote solubility, includingethyl or isopropyl alcohol, etc.

Composition Preparation

The liquid or gel dishwashing detergent compositions herein may beprepared by combining the essential and optional ingredients together inany convenient order using suitable agitation to form a homogeneousproduct. Preferred methods for making detergent compositions of the typedisclosed herein, and for preparing various components of suchcompositons, are described in greater detail in Ofosu-Asante: U.S. Pat.No. 5,474,710: Issued Dec. 12, 1995, incorporated herein by reference.

Dishwashing Method

Soiled dishes can be contacted with an effective amount, typically fromabout 0.5 ml. to about 20 ml. (per 25 dishes being treated), preferablyfrom about 3 ml. to about 10 ml., of the detergent composition of thepresent invention. The actual amount of liquid detergent compositionused will be based on the judgment of user, and will typically dependupon factors such as the particular product formulation of thecomposition, including the concentration of active ingredient in thecomposition, the number of soiled dishes to be cleaned, the degree ofsoiling on the dishes, and the like. The particular product formulation,in turn, will depend upon a number of factors, such as the intendedmarket (i.e., U.S., Europe, Japan, etc.) for the composition product.The following are examples of typical methods in which the detergentcompositions of the present invention may be used to clean dishes. Theseexamples are for illustrative purposes and are not intended to belimiting.

In a typical U.S. application, from about 3 ml. to about 15 ml.,preferably from about 5 ml. to about 10 ml. of a liquid detergentcomposition is combined with from about 1,000 ml. to about 10,000 ml.,more typically from about 3,000 ml. to about 5,000 ml. of water in asink having a volumetric capacity in the range of from about 5,000 ml.to about 20,000 ml., more typically from about 10,000 ml. to about15,000 ml. The detergent composition has a surfactant mixtureconcentration of from about 21% to about 44% by weight, preferably fromabout 25% to about 40% by weight. The soiled dishes are immersed in thesink containing the detergent composition and water, where they arecleaned by contacting the soiled surface of the dish with a cloth,sponge, or similar article. The cloth, sponge, or similar article may beimmersed in the detergent composition and water mixture prior to beingcontacted with the dish surface, and is typically contacted with thedish surface for a period of time ranging from about 1 to about 10seconds, although the actual time will vary with each application anduser. The contacting of the cloth, sponge, or similar article to thedish surface is preferably accompanied by a concurrent scrubbing of thedish surface.

In a typical European market application, from about 3 ml. to about 15ml., preferably from about 3 ml. to about 10 ml. of a liquid detergentcomposition is combined with from about 1,000 ml. to about 10,000 ml.,more typically from about 3,000 ml. to about 5,000 ml. of water in asink having a volumetric capacity in the range of from about 5,000 ml.to about 20,000 ml., more typically from about 10,000 ml. to about15,000 ml. The detergent composition has a surfactant mixtureconcentration of from about 20% to about 50% by weight, preferably fromabout 30% to about 40%, by weight. The soiled dishes are immersed in thesink containing the detergent composition and water, where they arecleaned by contacting the soiled surface of the dish with a cloth,sponge, or similar article. The cloth, sponge, or similar article may beimmersed in the detergent composition and water mixture prior to beingcontacted with the dish surface, and is typically contacted with thedish surface for a period of time ranging from about 1 to about 10seconds, although the actual time will vary with each application anduser. The contacting of the cloth, sponge, or similar article to thedish surface is preferably accompanied by a concurrent scrubbing of thedish surface.

In a typical Latin American market application, from about 1 ml. toabout 50 ml., preferably from about 2 ml. to about 10 ml. of a detergentcomposition is combined with from about 50 ml. to about 2,000 ml., moretypically from about 100 ml. to about 1,000 ml. of water in a bowlhaving a volumetric capacity in the range of from about 500 ml. to about5,000 ml., more typically from about 500 ml. to about 2,000 ml. Thedetergent composition has a surfactant mixture concentration of fromabout 5% to about 40% by weight, preferably from about 10% to about 30%by weight. The soiled dishes are cleaned by contacting the soiledsurface of the dish with a cloth, sponge, or similar article. The cloth,sponge, or similar article may be immersed in the detergent compositionand water mixture prior to being contacted with the dish surface, and istypically contacted with the dish surface for a period of time rangingfrom about 1 to about 10 seconds, although the actual time will varywith each application and user. The contacting of the cloth, sponge, orsimilar article to the dish surface is preferably accompanied by aconcurrent scrubbing of the dish surface.

Another method of use typical of Japanese dishwashing habits involvesdirect application of the detergent compositions herein, either neat ordiluted in a dispenser bottle, onto the soiled dishes to be cleaned.This can be accomplished by using a device for absorbing liquiddishwashing detergent, such as a sponge or dishrag, which is placeddirectly into a separate quantity of undiluted or somewhat dilutedliquid dishwashing composition for a period of time typically rangingfrom about 1 to about 5 seconds. The absorbing device, and consequentlythe undiluted or somewhat diluted liquid dishwashing composition, canthen be contacted individually with the surface of each of the soileddishes to remove food soil. The absorbing device is typically contactedwith each dish surface for a period of time ranging from about 1 toabout 10 seconds, although the actual time of application will bedependent upon factors such as the degree of soiling of the dish. Thecontacting of the absorbing device with the dish surface is preferablyaccompanied by concurrent scrubbing. Prior to contact and scrubbing,this method may involve immersing the soiled dishes into a water bathwithout any liquid dishwashing detergent. After scrubbing, the dish canbe rinsed under running water.

As used herein, all percentages, parts, and ratios are by weight unlessotherwise stated.

The following Examples illustrate the invention and facilitate itsunderstanding.

EXAMPLE I

A C₁₀ E₈ alcohol ethoxylate, calcium xylene sulfonate hydrotrope andprotease enzyme are all added, at levels of 6.0%, 5.0% and 0.05%respectively, (Composition A) to an aqueous light-duty dishwashingliquid (Composition B) comprising 20% sodium C₁₂₋₁₃alkylpolyethoxylate(12) sulfate, 4% C₁₂ glucose amide and 4% C₁₂alkyldimethyl amine oxide.

A home usage test is conducted with 120 panelists. Half of them use theprotease- and rinse/feel system-containing product (Composition A) andthe other half use the non-enzyme product (Composition B) for two weeks.They are then asked to compare the test product with their own product.Composition A is rated significantly higher (>95% confidence level) forproduct mildness, softness of hands, and smoothness of hands.Composition A also feels less slippery and slimy to the panelists thanComposition B.

Similarly, in a hand immersion test, panelists are asked to soak theirhands in the two different product solutions for 30 minutes each day,Monday through Thursday. Their hand conditions are then evaluated byexpert graders to evaluate the overall health and the extent offlakiness and panelist preferences between treatments are determined.Such testing indicates that Composition A treated skin is moister andsmoother than Composition B and is more preferred by the panelists.

EXAMPLE II

Light-duty liquid dishwashing detergent formulae are prepared asfollows:

    ______________________________________                                                        Composition                                                                   C      D        E                                             Ingredient        % Weight                                                    ______________________________________                                        Ammonium C.sub.12-13 alkyl ethoxy.sub.(1)                                                       28.50    28.50    28.50                                     sulfate                                                                       Coconut amine oxide                                                                             2.61     2.61     2.61                                      Betaine/Tetronic 704 ®                                                                      0.87/0.10                                                                              0.87/0.10                                                                              0.87/0.10                                 Alcohol Ethoxylate C.sub.8 E.sub.11                                                             5.00     0.00     5.00                                      Ammonium xylene sulfonate                                                                       0.00     4.00     4.00                                      Ethanol           4.00     4.00     4.00                                      Ammonium citrate  0.06     0.06     0.06                                      Magnesium chloride                                                                              3.32     3.32     3.32                                      Ammonium sulfate  0.08     0.08     0.08                                      Hydrogen peroxide 200 ppm  200 ppm  200 ppm                                   Perfume           0.18     0.18     0.18                                      Maxatase ® protease                                                                         0.50     0.50     0.50                                      Water and minors  Balance                                                     ______________________________________                                    

When Compositions C, D and E are used in a manual dishwashing operation,Composition E of the present invention which contains both C₈ E₁₁alcohol ethoxylate and xylene sulfonate hydrotrope provides a washingsolution that is easier to rinse off dishware than solutions formed fromeither Composition C or Composition D.

EXAMPLE III

Light-duty liquid dishwashing detergent formulae are prepared asfollows:

    ______________________________________                                                       Composition                                                                   F       G       H                                              Ingredient       % Weight                                                     ______________________________________                                        Ammonium C.sub.12-13 alkyl ethoxy.sub.(1)                                                      15.500    15.500  15.500                                     sulfate                                                                       Ammonium alkyl ethoxy (Ave 6.5)                                                                11.900    11.900  11.900                                     sulfate                                                                       Amine oxide      5.000     5.000   5.000                                      Alcohol Ethoxylate C.sub.10 E.sub.9                                                            4.000     5.000   4.000                                      Ammonium xylene sulfonate                                                                      4.000     5.000   4.000                                      Ethanol          5.500     5.500   5.500                                      Sodium chloride  1.000     1.000   1.000                                      Ammonium citrate 0.100     0.100   0.100                                      Perfume          0.090     0.090   0.090                                      Hydrogen peroxide                                                                              0.165     0.165   0.165                                      Protease B       0.000     0.050   0.150                                      Water and minors Balance                                                      ______________________________________                                    

A hand immersion test in which panelists are asked to soak their handstwice a day for 15 minutes each for four days results in significantlyimproved skin condition for Compositions (G) and (H) as compared tocontrol (F).

EXAMPLE IV

Light-duty liquid dishwashing detergent formulae are prepared asfollows:

    ______________________________________                                                          Composition                                                                   I     J       K                                             Ingredient          % Weight                                                  ______________________________________                                        Sodium C.sub.12-13 alkyl ethoxy (1)                                                               6.000   6.000   6.000                                     sulfate                                                                       Sodium C.sub.12-13 alkyl ethoxy (1-3)                                                             13.200  13.200  13.200                                    sulfate                                                                       C.sub.12 Glucose Amide                                                                            6.000   6.000   6.000                                     Coconut amine oxide 2.000   2.000   2.000                                     Hydrogen peroxide   0.006   0.006   0.006                                     Ethanol             5.500   5.500   5.500                                     Calcium xylene sulfonate                                                                          2.500   3.000   4.000                                     Neodol ® C.sub.11 E.sub.9                                                                     5.000   5.000   5.000                                     Sodium diethylene penta acetate (40%)                                                             0.030   0.030   0.030                                     Perfume             0.090   0.090   0.090                                     Magnesium++ (added as chloride)                                                                   0.060   0.060   0.060                                     sodium sulfate                                                                Savinase ® protease                                                                           0.000   0.050   0.010                                     Water and minors    Balance                                                   pH @ 10% (as made)  7.100   7.100   7.100                                     ______________________________________                                    

A hand immersion test consisting of eighteen panelists soaking theirhands hands in test products once a day for 30 minutes for a total offour days results in significant improvement in overall skin conditionfor both levels of protease-containing compositions (J and K) ascompared to control (I).

EXAMPLE V

Concentrated light-duty liquid dishwashing detergent compositions of thepresent invention are prepared as follows:

    ______________________________________                                                       Composition                                                                   L    M        N      O                                         Ingredient       % Weight                                                     ______________________________________                                        Diethylenetriamine penta acetate                                                               0.06   0.06     0.06 0.06                                    Neodol C.sub.10 E.sub.8                                                                        5.00   4.00     5.50 3.00                                    Ethanol          9.15   9.15     9.15 9.15                                    Magnesium hydroxide                                                                            2.18   2.18     2.18 2.18                                    Sucrose          1.50   1.50     1.50 1.50                                    Alkyl ethoxy(1.0) sulfate                                                                      34.14  34.14    34.14                                                                              34.24                                   Sodium hydroxide 1.13   1.13     1.13 1.13                                    Polyhydroxy fatty acid amide                                                                   6.50   6.50     6.50 6.50                                    Amine oxide      3.00   3.00     3.00 3.00                                    Cocoamidopropyl betaine                                                                        2.00   2.00     2.00 2.00                                    Perfume          0.23   0.23     0.23 0.23                                    Calcium xylene sulfonate                                                                       2.05   2.05     3.70 4.20                                    Alkyl diphenyl oxide                                                                           0.00   0.00     2.30 2.30                                    disulfonate.sup.1                                                             Calcium formate  0.53   0.53     1.14 1.14                                    Protease B       0.00   0.08     0.05 0.08                                    Water and minors Balance                                                      ______________________________________                                         .sup.1 DOWFAX 2A                                                         

Other compositions of the present invention are obtained when Protease Bis substituted with other proteases such as Maxacal®, Savinase®,Esperase® and BPN'.

What is claimed is:
 1. A light-duty liquid or gel dishwashing detergentcomposition that provides beneficial skin conditioning, skin feel andrinsability aesthetics, which composition comprises:(a) from about 5% to98% by weight of a detergent surfactant selected from the groupconsisting of polyhydroxy fatty acid amides; nonionic fattyalkylpolyglycosides; C₈₋₂₂ alkyl sulfates; C₉₋₁₅ alkyl benzenesulfonates; C₈₋₂₂ alkyl ether sulfates; C₈₋₂₂ olefin sulfonates; C₈₋₂₂paraffin sulfonates; C₈₋₂₂ alkyl glyceryl ether sulfonates; fatty acidester sulfonates; secondary alcohol sulfates; C₁₂₋₁₆ alkyl ethoxycarboxylates; C₁₁₋₁₆ secondary soaps; ampholytic detergent surfactants;zwitterionic detergent surfactants; and mixtures thereof; (b) from about3% to 20% by weight of a skin feel and rinsability enhancing systemwhich comprisesi) a nonionic surfactant component comprising C₆ -C₁₂alkanols condensed with from about 5 to 15 moles of ethylene oxide; andii) a hydrotrope component comprising C₁ -C₃ alkyl aryl sulfonates, C₆-C₁₂ alkanols, C₁ -C₆ carboxylic sulfates or sulfonates, urea, C₁ -C₄hydrocarboxylates, C₁ -C₄ carboxylates, C₂ -C₄ organic diacids ormixtures of these hydrotrope materials; in a nonionic surfactant tohydrotrope weight ratio of from about 10:1 to 1:10; and (c) from about0.001 to 5% by weight of an active protease enzyme; (d) from about 0.1to about 4 % by weight of magnesium ions;said composition having a pH offrom about 4 to
 11. 2. A composition according to claim 1 wherein:(a)the detergent surfactant comprises from about 20% to 60% by weight ofthe composition and is selected from the group consisting of polyhydroxyfatty acid amides; C₈₋₂₂ alkyl sulfates; C₈₋₂₂ alkyl ether sulfates;C₁₂₋₁₆ alkyl ethoxy carboxylates; and C₁₁ -C₁₆ secondary soaps; (b) theskin feel and rinsability enhancing system comprises from about 6% to12% by weight of the composition; (c) the nonionic surfactant componentof the skin feel and rinsability enhancing system comprises C₈ -C₁₁alkanols condensed with from about 8 to 12 moles of ethylene oxide; (d)the hydrotrope component of the skin feel and rinsability enhancingsystem is selected from the group consisting of sodium, potassium,calcium and ammonium xylene sulfonates; sodium, potassium, calcium andammonium toluene sulfonates; sodium, potassium, calcium and ammoniumcumene sulfonates; and sodium, potassium, calcium and and mixtures ofsaid hydrotrope materials; (e) the weight ratio of ethoxylated alcoholnonionic surfactant to hydrotrope within the skin feel and rinsabilityenhancing system ranges from about 1:5 to 5: 1; and (f) the proteaseenzyme component comprises from about 0.005% to 3% by weight of thecomposition and is a serine proteolytic enzyme obtained from Bacillussubtilis, Bacillus licheniformis or mixtures thereof; (g) from about 0.1to about 4 % by weight of magnesium ions.
 3. A composition according toclaim 2 which additionally contains from about 1% to 20% by weight of asuds booster selected from the group consisting of betaines, long chainalcohol ethoxylates, fatty acid amides, amine oxide semi-polarnonionics, sultaines, complex betaines, cationic surfactants andmixtures thereof.
 4. A composition according to claim 3 whichadditionally contains from about 0.1% to about 4% by weight of calciumions.
 5. A composition according to claim 4 which additionally containsfrom about 0.001% to about 10% of an enzyme stabilizing system.
 6. Acomposition according to claim 5 wherein the composition pH is betweenabout 7 and
 10. 7. A light-duty liquid or gel dishwashing detergentcomposition that provides beneficial skin conditioning, skin feel andrinsability aesthetics, which composition comprises:(a) from about 15%to 35% by weight of an anionic surfactant selected from the groupconsisting of C₈ -C₂₂ alkyl ether sulfates containing from about 1 to 30ethylene oxide moieties per molecule; (b) from about 3% to 8% by weightof a polyhydroxy fatty acid amide nonionic surfactant of the formula:##STR6## wherein R is a C₉ -C₁₇ alkyl or alkenyl, p is from 1 to 6; andZ is glycityl derived from a reduced sugar or alkoxylated derivativesthereof; (c) from about 4% to 8% by weight of an ethoxylated alcoholnonionic surfactant comprising one or more C₈ -C₁₁ alkanols condensedwith from about 8 to 12 moles of ethylene oxide; (d) from about 2% to 7%by weight of a hydrotrope selected from the group consisting of sodium,potassium, ammonium and calcium xylene and toluene sulfonates; (e) fromabout 0.1 to 40 Anson Units per kilogram of composition of a serineproteolytic enzyme obtained from Bacillus subtilis, Bacilluslicheniformis or mixtures thereof; and (f) from about 2% to 15% byweight of a suds booster selected from the group consisting of betainesand amine oxide semi-polar nonionic surfactants;said composition havinga pH of from about 7 to
 10. 8. A composition according to claim 7 whichadditionally contains from about 0.5% to 1% by weight of calcium ions.9. A composition according to claim 8 wherein said calcium and/ormagnesium ions are provided at least in part by compounds selected fromthe group consisting of hydroxides, oxides, chlorides, formates,acetates, and mixtures of these compounds.
 10. A composition accordingto claim 8 wherein calcium ions are provided at least in part by thehydrotrope material which is used in said composition.
 11. A method forsoaking hands in the context of a manual dishwashing operation, withreduced skin irritation resulting therefrom, which method comprises:1)preparing an aqueous dishwashing solution from an effective amount of adishwashing detergent composition according to claim 1; and 2) immersingthe hands of the dishwasher in said dishwashing solution for a period oftime which is effective to complete hand dishwashing operations.
 12. Ahandsoaking method according to claim 11 wherein the dishwasher's handsare immersed in said dishwashing solution for a period of at least about15 minutes.
 13. A handsoaking method according to claim 11 where thedishwaher's hands are immersed in said dishwashing solution for a periodof at least about 30 minutes.